For the first four months of the 2014 season, the Twins bullpen was among the team's bright spots. Even as the starting pitching faltered yet again — outside of Phil Hughes and every other Kyle Gibson start — the 'pen was holding things together and keeping Minnesota at least somewhat competitive.

The bullpen ERAs, by month this season:

March/April: 3.42; May: 3.86; June: 2.96; July: 2.53. The MLB average for the season is 3.58; the Twins were better than that mark three of the first four months, and certainly better than that overall number through the end of July.

But now we are seeing, yet again, the burden of an overtaxed bullpen. Early in the season, arms have an easier time compensating for the short starts (and therefore long bullpen nights) created by an underwhelming starting staff. But now? The Twins' bullpen ERA soared to 5.09 in August and has ballooned to 5.70 so far in September.

Being overworked doesn't explain all of it, since September callups can also contribute to a swollen ERA, but watching Casey Fien give up back-to-back homers in the ninth last night in his 71st game of the season (tied for third-most among pitchers in the majors) was another piece of anecdotal evidence that these lads are tired.

The same thing happened last year, with very good bullpen numbers through August before the 'pen ERA bloated to 4.96 in September.

This year, Minnesota's bullpen is tied for the second-most innings pitched in MLB. Last year, the Twins led the majors in that category, with the next-closest team a full 24 innings behind them.

It's yet another reason the Twins need to figure out this rotation. Not only has another disappointing year from starting pitchers wasted an unexpectedly good offensive showing, it is helping to turn another positive year from the bullpen into a negative finish.